Metal deactivator and a gasoline fuel containing the same



Patented Nov. 1, 1949 UNITED STATES PATENT OFFICE METAL nnac'rrva'ron AND A GASOLINE FUEL CONTAINING THE SAME Ralph B. Thompson, Riverside, Ill., assignor to Universal xOil Products Company, Chicago,- Ill., 1 ,a corporation of Delaware i "in; Drawing.

Application September 29, 1945, SerialNo.lil9,429' 1 1 iiciaim. (01.44 8

I tion at the low temperatures. sometimes-encounstabilizing organic compounds, and particularly 7 i to the stabilization of organic substances against deterioration by oxygencatalyzedin the presence I; of or by contact with certain oxidation promoters. While the present invention is applicable to pre- 1; venting such deterioration of fats, edible oils,

1 rubber, etc., it is particularly applicable to the 5 stabilization of olefin-containing hydrocarbon distillates, such as cracked or polymer gasolines.

One method of refining gasoline is the copper sweetening process, in which process the gasoline is contacted with a copper-containing reagent. As a result of this treatment, the sweetened gasoline usually contains relatively small amounts of copper compounds which have a catalytic effect on oxidation reactions resulting when the gasoline comes in contact with air.- In addition, gasolines come in contact with various metals in the course of refining, storing and shipping operations, and the metal may catalyze the oxidation reactions. In some cases, this may also result in the gasoline containing minor amounts of such metals as copper, iron, cobalt, nickel, chromium, lead, etc., which have a detrimental effect on the stabilization of the gasoline.

In a broad aspect, the present invention relates to a method of stabilizing an organic substance subject to oxidative deterioration in the presence of a metal or its compounds which normally catalyzes said deterioration, which comprises adding thereto a metal deactivator comprising a mixture of at least two salicylalaminophenols.

In' still another specific embodiment, the metal deactivator of the present invention may comprise a mixture of at least two salicylalaminoalkylphenols in which "the alkyl groups are difierent. I

In another embodiment of the invention, the metal deactivator may comprise a mixture of two or more of the various alkyl substituted ortho-aminophenols hereinbefore set forth. In other words, the unsubstituted 2-salicylalaminophenol need not necessarily be present.

While 2-salicylalaminophenol is a satisfactory deactivator, it is not sufliciently soluble in cracked gasoline to permit its use with gasolines containing increased amounts of metal compounds. One method of increasing the solubility of the metal deacti'ator in gasoline is by the use of an external solvent, such as ether, alcohol, ester, etc., but it has been found that the deactivator is not suiliciently soluble in readily available inexpensive solvents and it may be necessary to resort to the use of more expensive solvents. This is objectionable since it may increase the cost of the product to an exorbitant extent.

I have now found that a mixture of suitably substituted salicylalaminophenols improves the solubility of the deactivator, with the result that cylalamino 4-ethylphenol,'

tered in the use of gasoline.:. In addition to this important advantage, the mixed deactivators of the present invention are or unexpectedly higher potency. y

In one embodiment of the invention, the mixed metal deactivator may comprise z-salicylalaminophenol in admixture with one or more of the following; 2-salicylalamino-4-methy1phenol, z-sali- 2'-saiicylalamino-4- normal propylphenol, Z-salicylalamino-i-isopropylphenol, 2-salicylalamino-4-normal butylphen01, 2-salicylalamino l-isobutylphenol, 2-salicylalamino-4-sec-butylphenol, 2-salicylalamino-iter-butylphenol, 2-salicy1alamino-4 normal amylphenol, 2-salicylalamino-4-isoamylphenol, 2- salicylalamino 4-sec-amylphenol, 2-salicylalamino-4-ter amylph'enol, 2-salicy1alamino-4-normal hexylphenol, 2-salicylalamino-i-isohexylphen01, 2-salicylalamino-4-sec-hexylphenol, 2-salicylalamino-4-terhexylpheno1, 2-salicylalamino- 4- normal heptylphenol, 2-salicylalamino-4-isoheptylphenol, Z-salicylalamino-4-sec-heptylpheno], 2-sa1icylalamino-4 ter-heptylphenol, Z-salicylalamino-l-normal octylphenol, 2-salicylalamino--iso-octylphenol, 2-salicylalamino-4-secoctylphenol, 2--salicylalamino-4-ter-octoylphenol, etc.

While the preferred compounds comprise those in which the alkyl group is positioned para to the hydroxyl group (alkyl group being in the four position), it is understood that these alkyl groups may be located at difierent positions on the ring, and also that two or more alkyl groups may be attached to one or both of the rings. It

' is further understood that, in some cases, other may be prepared and utilized in the broad scope the deactivator will not crystallize out of solu- Y of the present invention will not necessarily be equivalent.

In general, it is preferred that the various substituents be substantially different, in order to avoid any possible isomorphous crystallization, which may occur when similar substituent groups are present.

The improved me'tal'deactivator of the present invention may be prepared by forming the various components separately and then blending either the pure compounds or solutions thereof, or the mixed deactivator may be prepared in one operation by mixing' the diiierent orthoaminophenols and coupling them with salicylaldehyde, in one step. In general, the metal deactivator of the present invention may be made by first form- 35 mixture warmed. The'product is purified by recrystallization.

Another advantage to the metal deactivator of the present invention is that it is completely compatible with known oxidation and gum inhibitors which are added to gasoline to minimize or prevent deleterious oxidation reactions which form gums and other undesirable products. Well known inhibitors include various phenolic, amino, and aminophenolic compounds. as well as fractions of wood tar oil, etc., and are usually added to gasoline in concentrations of 0.001% to 0.1% by weight. Some of these inhibitors are marketed in the form of a solution in asuitable solvent, such as alcohol, ether, etc., and in most cases the solvent for the inhibitor may also function as the solvent for the metal deactivator of the present invention. In one embodiment of the invention, the inhibitor and the metal deactivator may be prepared as a mixture in a solvent, and the combined inhibitor and deactivator may be marketed as a single commodity of two-fold purpose.

In another embodiment of the invention, the metal deactivator may be marketed as such or may be dissolved in a suitable solvent and the solution marketed. Any suitable solventmay be employed including alcohols, such as methyl alcohol, ethyl alcohol, isopropyl alcohol, sec-butyl alcohol, etc., various ethers and esters, hydrocarbons such as benzene, Xylene, etc., or mixtures of these various solvents. The metal deactivator of the present invention has a tendency to react with solvents such as acetone and furfural and for this reason the use of these solvents is not preferred because of the resulting reduction in effectiveness after long periods of time. Pyridine is a nitrogen base and therefore is not particularly desirable as anadditive to motor fuel and further it is relatively expensive. It therefore is not generally desirable as a solvent for the present purpose. An alcohol or ether solvent is particularly preferred, both because of their cheap cost and ready availability and also because they do not adversely affect the metal deactivator;

The metal deactivator of the present invention may be used in gasoline in amounts of about 0.0001% to about 0.01% and may be added to the gasoline as such, in a suitable solvent, or in an admixture with the oxidation inhibitor, in the manner hereinabove set forth.

It is understood that the metal deactivators of the present invention are generally utilized in addition to the oxidation inhibitors hereinbefore set forth and that the function of the metal deactivator is entirely distinct from the function of the inhibitor. For example, the oxidation inhibitor does not suppress the catalytic action of the metal to any considerable extent and, on the other hand, the metal deactivator does not suppress oxidation reactions per se, to any considerable extent but serves only to deactivate the metal compounds and thereby destroy the catalytic effect thereof to enhance oxidation reactions.

The following examples are introduced to illustrate further the novelty and utility of the present invention but not with the intention of unduly limiting the same.

EXAMPLEI The following example shows the temperature of crystallization of (l) 2-salicylalaminophenol, (2) 2-salicylalamino--ter-amylphenol, (3) 2- to the gasoline.

Q salicylalamino4-sec-butylphenol, and (4) 2- salicylalamino-i-ethylphenol. in comparison with (5) a mixture of 15% 2-salicyialaminophenol and 85% 2-saiicylalamino-i ter-amylphenol, (6) a mixture of 10% 2-salicylalaminophenol, 45% 2-salicylalaminoi-ter-amylphenol, and 45% 2-salicylalamino-4-sec-butylphenol, and

('7) a mixture of 2-salicylalaminophenol,'

65% 2-salicylalamino-4-ter-amylphenol and 2-salicylalamino-4-ethylphenol.

After being separately prepared, all of the above metal deactivators were dissolved in separate portions of anhydrous sec-butyl-alcohol solvent. The amount of metal deactivator in the solvent is indicated in the following table:

Table I Temperature of Cryst llization, F.

Percent by weight in solvcn t Deactivator 2-sulicylainmi o-l-cthylphcuoi Mixture of 15% 'Z-SRHGYiiltliTllnophenol and 85% 2-s-ilicylulnmino-l-tcr-amyl- 80 0 (6) nminophom uiamium-l-Li 1 -:n y

and Z-snlic .(7) Mixturcol15%2-sulicy aminophcnol, 2-snlicyl'ilamino-4-tcr-amylphcn0l, and 20% 2-s-ilicylul1imino-4- cthylphcnol 30 Less than l0 It is apparent from the above data'that the temperature of crystallization of the mixed deactivators is considerably lower, and therefore that no difficulty in commercial use should be encountered, particularly with the three component mixture comprising 2 -salicylaiaminophenol,' 2-salicylalamino-a-ter-amylphenol, and 2-salicylalamino-4-ethylphenol.

EXAMPLE II As heretoforementioned, the potency of the mixed metal deactivators is higher than that of the single compounds and this is illustrated in Table II. In this series of tests, some of the metal deactivator solutions specified in Example I were added to Pennsylvania thermally cracked gasoline in an amount of 0.0007% by weight. In addition, 0.01% of an inhibitor comprising a major proportion of an aminophenol and a minor proportion of a phenylene diamine was added 1 mg. of copper per liter was also added, and the induction periods obtains on the various samples are given below.

The induction period of the inhibited gasoline without added copper was 570 minutes.

In the absence of any metal deactivator, the induction period of the inhibited gasoline fell to 200 minutes upon the addition of 1 per per liter.

Example III In another series of tests, similar to Example I, but using ethyl acetate as the solvent, the folmg. of coplowing temperatures of crystallization were determined:

I Table III Per cent by weight in solvent Deactlvator L055 than EXAMPLE IV In another series of tests, separate solutions were prepared of various metal deactivators in 80 octane all-purpose gasoline comprising a mixture of cracked and straight-run gasolines. The various metal deactivator solutions were as follows: (1) a solution of 0.5% by weight of 2-salicylamino-4-tetramylphenol. (2) a solution of 0.5% by weight of 2-salicylalamino-4-sec-butylphenol, (3) a solution of 0.5% by weight of a mixture of 2-salicylalaminophenol, 45% 2- salicylalamino-4-ter-amylphenol and 45% 2- salicylalamino-i-sec-butylphenol, and (4) a solution of 0.5% by weight of a mixture of 2- salicylalaminophenol; 65% 2-salicylalamino-4- ter-amylphenol and 2-salicy1alamino-4- ethylphenol. These solutions were stored at -5 F. and after 2 to 3 hours the solution of 2-salicylala'mino-i-ter-amylphenol and the solution of 2- salicylalamino-4-sec-butylphenol crystallized, but the other two solutions comprising the mixed metal deactivators, did not crystallize after stoage at -5 F.

I claim as my invention:

1. A method of stabilizing olefinic gasoline subject to oxidative deterioration in-the presence of a metal which normally catalyzes said deterioration, which comprises adding thereto a metal deactivator comprising a mixture of z-salicylalaminophenol and a 2-salicylalamino-alkylphenol.

2. The process of claim Lfurther characterized in that said deactivator comprises a mixture of 2-salicylalaminophenol and at least two 2-salicylalamino-alkylphenols, in which the alkyl groups are diil'erent.

3. The method of stabilizing gasoline containing unsaturated hydrocarbons which tend to form gums and containing a metal which normally catalyzes oxidative deterioration, which comprises adding to said gasoline an inhibitor to prevent said gum formation and a smaller amount of a. metal deactivator comprising a mixture of z-salicylalaminophenol and a z-salicylalaminoalkylphenol. I

4. The process of claim 3 further characterized in that said mixture comprises Z-salicylalaminophenol and a 2-saiicylalamino-4-alkylpheno1.

5. The process of claim 3 further characterized in that said mixture comprises z-salicylalaminophenol and at least two 2-salicylalamino-4-alkylphenols in which the alkyl groups are difierent.

6. Olefinlc gasoline subject to oxidative deteriminophenol 10.A mixture of 2-salicylalarninophenol and 2-sa1icyialamino-4-alkylphenol.

11-. A mixture of 2r-salicylalaminophenol at least two 2-salicylalamino-4-alkylphenols in which the alkyl groups are different.

12. A method of stabilizing olefinic gasoline subject to oxidative deterioration in the presence of a metal which normally catalyzes said deteri-V oration, which comprises adding thereto a metal deactivator comprising a mixture of 2-salicylalaand a 2-salicylalamino-4-alkylphenol wherein the alkyl radical contains from 1 to 8 carbon atoms.

13. The method of stabilizing gasoline containing unsaturated hydrocarbons which tend to form gums and containing a metal which normally catalyzes oxidative deterioration,- which comprises adding to said gasoline an inhibitor to prevent said gum formation and a smaller amount of a metal deactivator comprising a mixture of 2-salicylalaminophenol and a 2-sa1icylalamino-l-alkylphenol wherein the alkyl radical contains from 1 to 8 carbon atoms.

14. Olefinlc gasoline subject to oxidative deterioration in the presence of a metal which normally catalyzes said deterioration containing as a deactivator of the catalytic eifect of said metal,

a mixture of 2-salicylalaminophenol and a 2-sa1icylalaminol-alkylphenol wherein the alkyl radical contains from 1 to 8 carbon atoms.

15. A mixture of 2-salicylalaminophenol and a 2-salicylal-amino-4-alkylpheno1 wherein the alkyl radical contains from 1 to 8 carbon'atoms.

16. The method of stabilizing gasoline contaming unsaturated hydrocarbons which tend to form gums and containing a metal which normally catalyzes oxidative deterioration, which comprises adding to said gasoline an inhibitor to prevent said I gum formation and a smaller amount of a metal deactivator comprising a mixture of 2-salicylalaminophenol, 2-salicylalamino- 4-ter-amylphenol, and 2-salicylalamino-4-ethylphenol.

17. Olefinic gasoline subject to oxidative deterioration in the presence of a metal which normally catalyzes said deterioration containing as as a ueactivator of the catalytic effect of said metal, a mixture of 2 salicylalaminophenol, 2- salicylalamino-4-t'er-amylphenol, and 2-salicylalamino-4-ethylphenol.

RALPH B. THOMPSON.

REFERENCES CITED UNITED STATES PATENTS Name Date Chemcek July 15. 1941 Number 

